Content Provider
DataCite Metadata Store (German National Library of Science and Technology)
4,534
NOAA NCEI Environmental Data Archive (via DataONE)
267
Research Data Australia (Australian National Data Service - ANDS)
75
LeibnizOpen (The Leibniz Association)
59
Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center)
46
Unknown
46
Directory of Open Access Journals: DOAJ Articles
37
WikiBooks - Open-content textbooks
26
Copernicus Publications: E-Journals
25
Niedersächsisches Online-Archiv NOA
21
Frontiers: Figshare
15
Natural Environment Research Council: NERC Open Research Archive
13
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel)
13
Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe)
12
PANGAEA - Data Publisher for Earth & Environmental Science
12
Digital.CSIC (Spanish National Research Council)
9
University of California: eScholarship
9
Université de Nantes: HAL-UNIV-NANTES
8
Archimer (Archive Institutionnelle de l'Ifremer - Institut français de recherche pour l'exploitation de la mer)
7
Max Planck Society: MPG.PuRe
7
USGS Science Data Catalog (via DataONE)
7
University of East Anglia: UEA Digital Repository
7
University of Groningen research database
7
Media SuUB Bremen (Staats- und Universitätsbibliothek Bremen)
6
PubMed Central (PMC)
6
University of Southampton: e-Prints Soton
6
Arctic Data Center (via DataONE)
5
National Institute of Polar Research Repository, Japan
5
Xiamen University Institutional Repository
5
Institut national des sciences de l'Univers: HAL-INSU
4
Zenodo
4
DIAL@UCLouvain (Université catholique de Louvain)
3
Flanders Marine Institute (VLIZ): Open Marine Archive (OMA)
3
OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research)
3
Oxford University Press (via Crossref)
3
Renate - Repositorium für Naturwissenschaften und Technik (TIB Hannover)
3
Wageningen UR (University & Research Centre): Digital Library
3
Woods Hole Scientific Community: WHOAS (Woods Hole Open Access Server)
3
Aarhus University: Research
2
Australian National University: ANU Digital Collections
2
BORIS (Bern Open Repository and Information System, University of Bern)
2
DIAL@USL-B (Université Saint-Louis, Bruxelles)
2
Defense Technical Information Center: DTIC Technical Reports database
2
Dryad Digital Repository (Duke University)
2
Frontiers (Publisher)
2
IEDA: US Antarctic Program Data Center (via DataONE)
2
Institutional Knowledge (InK) at Singapore Management University
2
MDPI Open Access Publishing
2
NASA Technical Reports Server (NTRS)
2
Plymouth Marine Science Electronic Archive (PlyMSEA - Plymouth Marine Laboratory, PML)
2
more ...